--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/pomo/plural-forms.php Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,343 @@
+<?php
+
+/**
+ * A gettext Plural-Forms parser.
+ *
+ * @since 4.9.0
+ */
+class Plural_Forms {
+ /**
+ * Operator characters.
+ *
+ * @since 4.9.0
+ * @var string OP_CHARS Operator characters.
+ */
+ const OP_CHARS = '|&><!=%?:';
+
+ /**
+ * Valid number characters.
+ *
+ * @since 4.9.0
+ * @var string NUM_CHARS Valid number characters.
+ */
+ const NUM_CHARS = '0123456789';
+
+ /**
+ * Operator precedence.
+ *
+ * Operator precedence from highest to lowest. Higher numbers indicate
+ * higher precedence, and are executed first.
+ *
+ * @see https://en.wikipedia.org/wiki/Operators_in_C_and_C%2B%2B#Operator_precedence
+ *
+ * @since 4.9.0
+ * @var array $op_precedence Operator precedence from highest to lowest.
+ */
+ protected static $op_precedence = array(
+ '%' => 6,
+
+ '<' => 5,
+ '<=' => 5,
+ '>' => 5,
+ '>=' => 5,
+
+ '==' => 4,
+ '!=' => 4,
+
+ '&&' => 3,
+
+ '||' => 2,
+
+ '?:' => 1,
+ '?' => 1,
+
+ '(' => 0,
+ ')' => 0,
+ );
+
+ /**
+ * Tokens generated from the string.
+ *
+ * @since 4.9.0
+ * @var array $tokens List of tokens.
+ */
+ protected $tokens = array();
+
+ /**
+ * Cache for repeated calls to the function.
+ *
+ * @since 4.9.0
+ * @var array $cache Map of $n => $result
+ */
+ protected $cache = array();
+
+ /**
+ * Constructor.
+ *
+ * @since 4.9.0
+ *
+ * @param string $str Plural function (just the bit after `plural=` from Plural-Forms)
+ */
+ public function __construct( $str ) {
+ $this->parse( $str );
+ }
+
+ /**
+ * Parse a Plural-Forms string into tokens.
+ *
+ * Uses the shunting-yard algorithm to convert the string to Reverse Polish
+ * Notation tokens.
+ *
+ * @since 4.9.0
+ *
+ * @param string $str String to parse.
+ */
+ protected function parse( $str ) {
+ $pos = 0;
+ $len = strlen( $str );
+
+ // Convert infix operators to postfix using the shunting-yard algorithm.
+ $output = array();
+ $stack = array();
+ while ( $pos < $len ) {
+ $next = substr( $str, $pos, 1 );
+
+ switch ( $next ) {
+ // Ignore whitespace
+ case ' ':
+ case "\t":
+ $pos++;
+ break;
+
+ // Variable (n)
+ case 'n':
+ $output[] = array( 'var' );
+ $pos++;
+ break;
+
+ // Parentheses
+ case '(':
+ $stack[] = $next;
+ $pos++;
+ break;
+
+ case ')':
+ $found = false;
+ while ( ! empty( $stack ) ) {
+ $o2 = $stack[ count( $stack ) - 1 ];
+ if ( $o2 !== '(' ) {
+ $output[] = array( 'op', array_pop( $stack ) );
+ continue;
+ }
+
+ // Discard open paren.
+ array_pop( $stack );
+ $found = true;
+ break;
+ }
+
+ if ( ! $found ) {
+ throw new Exception( 'Mismatched parentheses' );
+ }
+
+ $pos++;
+ break;
+
+ // Operators
+ case '|':
+ case '&':
+ case '>':
+ case '<':
+ case '!':
+ case '=':
+ case '%':
+ case '?':
+ $end_operator = strspn( $str, self::OP_CHARS, $pos );
+ $operator = substr( $str, $pos, $end_operator );
+ if ( ! array_key_exists( $operator, self::$op_precedence ) ) {
+ throw new Exception( sprintf( 'Unknown operator "%s"', $operator ) );
+ }
+
+ while ( ! empty( $stack ) ) {
+ $o2 = $stack[ count( $stack ) - 1 ];
+
+ // Ternary is right-associative in C
+ if ( $operator === '?:' || $operator === '?' ) {
+ if ( self::$op_precedence[ $operator ] >= self::$op_precedence[ $o2 ] ) {
+ break;
+ }
+ } elseif ( self::$op_precedence[ $operator ] > self::$op_precedence[ $o2 ] ) {
+ break;
+ }
+
+ $output[] = array( 'op', array_pop( $stack ) );
+ }
+ $stack[] = $operator;
+
+ $pos += $end_operator;
+ break;
+
+ // Ternary "else"
+ case ':':
+ $found = false;
+ $s_pos = count( $stack ) - 1;
+ while ( $s_pos >= 0 ) {
+ $o2 = $stack[ $s_pos ];
+ if ( $o2 !== '?' ) {
+ $output[] = array( 'op', array_pop( $stack ) );
+ $s_pos--;
+ continue;
+ }
+
+ // Replace.
+ $stack[ $s_pos ] = '?:';
+ $found = true;
+ break;
+ }
+
+ if ( ! $found ) {
+ throw new Exception( 'Missing starting "?" ternary operator' );
+ }
+ $pos++;
+ break;
+
+ // Default - number or invalid
+ default:
+ if ( $next >= '0' && $next <= '9' ) {
+ $span = strspn( $str, self::NUM_CHARS, $pos );
+ $output[] = array( 'value', intval( substr( $str, $pos, $span ) ) );
+ $pos += $span;
+ continue;
+ }
+
+ throw new Exception( sprintf( 'Unknown symbol "%s"', $next ) );
+ }
+ }
+
+ while ( ! empty( $stack ) ) {
+ $o2 = array_pop( $stack );
+ if ( $o2 === '(' || $o2 === ')' ) {
+ throw new Exception( 'Mismatched parentheses' );
+ }
+
+ $output[] = array( 'op', $o2 );
+ }
+
+ $this->tokens = $output;
+ }
+
+ /**
+ * Get the plural form for a number.
+ *
+ * Caches the value for repeated calls.
+ *
+ * @since 4.9.0
+ *
+ * @param int $num Number to get plural form for.
+ * @return int Plural form value.
+ */
+ public function get( $num ) {
+ if ( isset( $this->cache[ $num ] ) ) {
+ return $this->cache[ $num ];
+ }
+ return $this->cache[ $num ] = $this->execute( $num );
+ }
+
+ /**
+ * Execute the plural form function.
+ *
+ * @since 4.9.0
+ *
+ * @param int $n Variable "n" to substitute.
+ * @return int Plural form value.
+ */
+ public function execute( $n ) {
+ $stack = array();
+ $i = 0;
+ $total = count( $this->tokens );
+ while ( $i < $total ) {
+ $next = $this->tokens[$i];
+ $i++;
+ if ( $next[0] === 'var' ) {
+ $stack[] = $n;
+ continue;
+ } elseif ( $next[0] === 'value' ) {
+ $stack[] = $next[1];
+ continue;
+ }
+
+ // Only operators left.
+ switch ( $next[1] ) {
+ case '%':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 % $v2;
+ break;
+
+ case '||':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 || $v2;
+ break;
+
+ case '&&':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 && $v2;
+ break;
+
+ case '<':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 < $v2;
+ break;
+
+ case '<=':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 <= $v2;
+ break;
+
+ case '>':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 > $v2;
+ break;
+
+ case '>=':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 >= $v2;
+ break;
+
+ case '!=':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 != $v2;
+ break;
+
+ case '==':
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 == $v2;
+ break;
+
+ case '?:':
+ $v3 = array_pop( $stack );
+ $v2 = array_pop( $stack );
+ $v1 = array_pop( $stack );
+ $stack[] = $v1 ? $v2 : $v3;
+ break;
+
+ default:
+ throw new Exception( sprintf( 'Unknown operator "%s"', $next[1] ) );
+ }
+ }
+
+ if ( count( $stack ) !== 1 ) {
+ throw new Exception( 'Too many values remaining on the stack' );
+ }
+
+ return (int) $stack[0];
+ }
+}